#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <string.h>
#include <assert.h>
/*
strcat
char * strcat ( char * destination, const char * source );
*/
//int main()
//{
//	char str[80];
//	strcpy(str, "these ");
//	strcat(str, "strings ");
//	strcat(str, "are ");
//	strcat(str, "concatenated.");
//	puts(str);
//	return 0;
//}
char* my_strcpy(char* dest, const char* src)
{
	char* ret = dest;
	assert(dest != NULL);
	assert(src != NULL);
	while (*dest)
	{
		dest++;
	}
	while ((*dest++ = *src++))
	{
		;
	}
	return ret;
}
int main()
{
	char str[80] = {0};
	my_strcpy(str, "these ");
	my_strcpy(str, "strings ");
	my_strcpy(str, "are ");
	my_strcpy(str, "concatenated.");
	puts(str);
	return 0;
}